title: Transition metal-free one-pot cascade synthesis of 7-oxa-2-azatricyclo[7.4.0.0(2,6)]trideca-1(9),10,12-trien-3-ones from biomass-derived levulinic acid under mild conditions.
abstract: An efficient, environmentally benign, transition-metal free, tandem C-N, C-O bond formation reaction is developed for the synthesis of tricyclic 7-oxa-2-azatricyclo[7.4.0.0(2,6)]trideca-1(9),10,12-trien-3-ones and their homologs from easily available starting materials, including renewable levulinic acid, a keto acid. The reaction of keto acids with methyl chloroformate and variously substituted o-aminobenzyl alcohols using triethylamine as a base in toluene at room temperature gave good to excellent yields. This newly developed protocol was successfully utilized for the synthesis of a variety of polycyclic 7-oxa-2-azatricyclo[7.4.0.0(2,6)]trideca-1(9),10,12-trien-3-ones and related compounds.
authors.affiliation: Department of Chemistry, Acadia University, Wolfville, Canada B4P 2R6. ajha@acadiau.ca.
authors.forename: Amitabh
authors.initials: A
authors.lastname: Jha
authors.forename: Ajaya B
authors.initials: AB
authors.lastname: Naidu
authors.forename: Ashraf M
authors.initials: AM
authors.lastname: Abdelkhalik
mesh_terms: D048588:Benzoxazines / Q000138:chemical synthesis* / Q000737:chemistry; D018533:Biomass; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D007982:Levulinic Acids / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D048588:Benzoxazines; D006575:Heterocyclic Compounds, 3-Ring; D007982:Levulinic Acids; C032246:levulinic acid